public class ifelse {
    public static void main(String[] args) {
        int score=80;
        if(score>=90)
        {
            System.out.println('A');
        }else if(score>=80)
        {
            System.out.println('B');
        } else if (score>=60) {
            System.out.println('C');
        }else {
            System.out.println('D');
        }
    }
}
